body {
    background: #eef;
    height: 100vh;
    overflow: hidden;
    display: -webkit-box;
    display: -ms-flexbox;
    display: flex;
    -webkit-box-pack: center;
    -ms-flex-pack: center;
    justify-content: center;
    -webkit-box-align: center;
    -ms-flex-align: center;
    align-items: center;
}
#sky {
    margin-top: -60px;
    -webkit-perspective: 400px;
    perspective: 400px;
    -webkit-filter: drop-shadow(0px 150px 10px rgba(0, 0, 0, 0.2));
    filter: drop-shadow(0px 150px 10px rgba(0, 0, 0, 0.2));
    -webkit-transform-style: preserve-3d;
    transform-style: preserve-3d;
}
#sky div {
    -webkit-transform-style: preserve-3d;
    transform-style: preserve-3d;
}
#sky .bird {
    -webkit-animation: fly 10000ms linear infinite;
    animation: fly 10000ms linear infinite;
}
#sky .bird .wind {
    position: absolute;
    left: 50%;
    width: 4px;
    height: 200px;
    margin-left: -2px;
    border-radius: 999px;
    overflow: hidden;
}
#sky .bird .wind:nth-child(1) {
    -webkit-transform: translate3d(-157px, 138px, -68px) rotateY(90deg);
    transform: translate3d(-157px, 138px, -68px) rotateY(90deg);
}
#sky .bird .wind:nth-child(1)::before {
    content: '';
    position: absolute;
    width: 4px;
    height: 300px;
    background: rgba(100, 200, 90, 0.3);
    border-radius: 999px;
    -webkit-transform: translateY(-300px);
    transform: translateY(-300px);
    -webkit-animation: wind 1935ms 1233ms linear infinite;
    animation: wind 1935ms 1233ms linear infinite;
}
#sky .bird .wind:nth-child(2) {
    -webkit-transform: translate3d(98px, 75px, 2px) rotateY(90deg);
    transform: translate3d(98px, 75px, 2px) rotateY(90deg);
}
#sky .bird .wind:nth-child(2)::before {
    content: '';
    position: absolute;
    width: 4px;
    height: 300px;
    background: rgba(100, 200, 92, 0.3);
    border-radius: 999px;
    -webkit-transform: translateY(-300px);
    transform: translateY(-300px);
    -webkit-animation: wind 1048ms 4242ms linear infinite;
    animation: wind 1048ms 4242ms linear infinite;
}
#sky .bird .wind:nth-child(3) {
    -webkit-transform: translate3d(181px, 103px, 66px) rotateY(90deg);
    transform: translate3d(181px, 103px, 66px) rotateY(90deg);
}
#sky .bird .wind:nth-child(3)::before {
    content: '';
    position: absolute;
    width: 4px;
    height: 300px;
    background: rgba(100, 200, 174, 0.3);
    border-radius: 999px;
    -webkit-transform: translateY(-300px);
    transform: translateY(-300px);
    -webkit-animation: wind 1577ms 4135ms linear infinite;
    animation: wind 1577ms 4135ms linear infinite;
}
#sky .bird .wind:nth-child(4) {
    -webkit-transform: translate3d(171px, -100px, 100px) rotateY(90deg);
    transform: translate3d(171px, -100px, 100px) rotateY(90deg);
}
#sky .bird .wind:nth-child(4)::before {
    content: '';
    position: absolute;
    width: 4px;
    height: 300px;
    background: rgba(100, 200, 209, 0.3);
    border-radius: 999px;
    -webkit-transform: translateY(-300px);
    transform: translateY(-300px);
    -webkit-animation: wind 1176ms 3610ms linear infinite;
    animation: wind 1176ms 3610ms linear infinite;
}
#sky .bird .wind:nth-child(5) {
    -webkit-transform: translate3d(155px, -139px, 45px) rotateY(90deg);
    transform: translate3d(155px, -139px, 45px) rotateY(90deg);
}
#sky .bird .wind:nth-child(5)::before {
    content: '';
    position: absolute;
    width: 4px;
    height: 300px;
    background: rgba(100, 200, 168, 0.3);
    border-radius: 999px;
    -webkit-transform: translateY(-300px);
    transform: translateY(-300px);
    -webkit-animation: wind 1154ms 1412ms linear infinite;
    animation: wind 1154ms 1412ms linear infinite;
}
#sky .bird .wind:nth-child(6) {
    -webkit-transform: translate3d(61px, 33px, 72px) rotateY(90deg);
    transform: translate3d(61px, 33px, 72px) rotateY(90deg);
}
#sky .bird .wind:nth-child(6)::before {
    content: '';
    position: absolute;
    width: 4px;
    height: 300px;
    background: rgba(100, 200, 242, 0.3);
    border-radius: 999px;
    -webkit-transform: translateY(-300px);
    transform: translateY(-300px);
    -webkit-animation: wind 2079ms 4956ms linear infinite;
    animation: wind 2079ms 4956ms linear infinite;
}
#sky .bird .wind:nth-child(7) {
    -webkit-transform: translate3d(-61px, 37px, 43px) rotateY(90deg);
    transform: translate3d(-61px, 37px, 43px) rotateY(90deg);
}
#sky .bird .wind:nth-child(7)::before {
    content: '';
    position: absolute;
    width: 4px;
    height: 300px;
    background: rgba(100, 200, 195, 0.3);
    border-radius: 999px;
    -webkit-transform: translateY(-300px);
    transform: translateY(-300px);
    -webkit-animation: wind 2506ms 2873ms linear infinite;
    animation: wind 2506ms 2873ms linear infinite;
}
#sky .bird .wind:nth-child(8) {
    -webkit-transform: translate3d(-100px, 16px, 70px) rotateY(90deg);
    transform: translate3d(-100px, 16px, 70px) rotateY(90deg);
}
#sky .bird .wind:nth-child(8)::before {
    content: '';
    position: absolute;
    width: 4px;
    height: 300px;
    background: rgba(100, 200, 66, 0.3);
    border-radius: 999px;
    -webkit-transform: translateY(-300px);
    transform: translateY(-300px);
    -webkit-animation: wind 1962ms 1394ms linear infinite;
    animation: wind 1962ms 1394ms linear infinite;
}
#sky .bird .wind:nth-child(9) {
    -webkit-transform: translate3d(114px, 26px, -30px) rotateY(90deg);
    transform: translate3d(114px, 26px, -30px) rotateY(90deg);
}
#sky .bird .wind:nth-child(9)::before {
    content: '';
    position: absolute;
    width: 4px;
    height: 300px;
    background: rgba(100, 200, 30, 0.3);
    border-radius: 999px;
    -webkit-transform: translateY(-300px);
    transform: translateY(-300px);
    -webkit-animation: wind 2489ms 2975ms linear infinite;
    animation: wind 2489ms 2975ms linear infinite;
}
#sky .bird .wind:nth-child(10) {
    -webkit-transform: translate3d(-57px, -48px, 33px) rotateY(90deg);
    transform: translate3d(-57px, -48px, 33px) rotateY(90deg);
}
#sky .bird .wind:nth-child(10)::before {
    content: '';
    position: absolute;
    width: 4px;
    height: 300px;
    background: rgba(100, 200, 124, 0.3);
    border-radius: 999px;
    -webkit-transform: translateY(-300px);
    transform: translateY(-300px);
    -webkit-animation: wind 2309ms 3147ms linear infinite;
    animation: wind 2309ms 3147ms linear infinite;
}
#sky .bird .wind:nth-child(11) {
    -webkit-transform: translate3d(139px, 107px, 24px) rotateY(90deg);
    transform: translate3d(139px, 107px, 24px) rotateY(90deg);
}
#sky .bird .wind:nth-child(11)::before {
    content: '';
    position: absolute;
    width: 4px;
    height: 300px;
    background: rgba(100, 200, 200, 0.3);
    border-radius: 999px;
    -webkit-transform: translateY(-300px);
    transform: translateY(-300px);
    -webkit-animation: wind 1365ms 2503ms linear infinite;
    animation: wind 1365ms 2503ms linear infinite;
}
#sky .bird_body {
    position: relative;
    width: 30px;
    height: 40px;
    background: #a7b1d5;
}
#sky .bird_head {
    position: absolute;
    top: -30px;
    border-right: 15px solid transparent;
    border-bottom: 30px solid #779dcc;
    border-left: 15px solid transparent;
    -webkit-transform-origin: 50% 100%;
    transform-origin: 50% 100%;
    -webkit-transform: rotateX(-20deg);
    transform: rotateX(-20deg);
}
#sky .bird_wing_left {
    position: absolute;
    left: -30px;
    height: 30px;
    border-right: 30px solid #a297ff;
    border-bottom: 10px solid transparent;
    -webkit-transform-origin: 100% 0;
    transform-origin: 100% 0;
    -webkit-animation: wingLeft 1000ms cubic-bezier(0.36, 0.1, 0.16, 1) infinite alternate;
    animation: wingLeft 1000ms cubic-bezier(0.36, 0.1, 0.16, 1) infinite alternate;
}
#sky .bird_wing_left_top {
    position: absolute;
    left: -30px;
    border-right: 30px solid #9296de;
    border-bottom: 30px solid transparent;
    -webkit-transform-origin: 100% 0;
    transform-origin: 100% 0;
    -webkit-animation: wingLeft 1000ms cubic-bezier(0.545, 0.08, 0.52, 0.975) infinite alternate;
    animation: wingLeft 1000ms cubic-bezier(0.545, 0.08, 0.52, 0.975) infinite alternate;
}
#sky .bird_wing_right {
    position: absolute;
    left: 30px;
    height: 30px;
    border-left: 30px solid #8399e6;
    border-bottom: 10px solid transparent;
    -webkit-transform-origin: 0 0;
    transform-origin: 0 0;
    -webkit-animation: wingRight 1000ms cubic-bezier(0.36, 0.1, 0.16, 1) infinite alternate;
    animation: wingRight 1000ms cubic-bezier(0.36, 0.1, 0.16, 1) infinite alternate;
}
#sky .bird_wing_right_top {
    position: absolute;
    border-left: 30px solid #bc73e1;
    border-bottom: 30px solid transparent;
    -webkit-transform-origin: 0 0;
    transform-origin: 0 0;
    -webkit-animation: wingRight 1000ms cubic-bezier(0.545, 0.08, 0.52, 0.975) infinite alternate;
    animation: wingRight 1000ms cubic-bezier(0.545, 0.08, 0.52, 0.975) infinite alternate;
}
#sky .bird_tail_left {
    position: absolute;
    top: 40px;
    border-right: 30px solid transparent;
    border-top: 40px solid #c279f7;
    -webkit-transform-origin: 50% 0;
    transform-origin: 50% 0;
    -webkit-transform: rotateX(-20deg);
    transform: rotateX(-20deg);
}
#sky .bird_tail_right {
    position: absolute;
    top: 40px;
    border-left: 30px solid transparent;
    border-top: 40px solid #ae79db;
    -webkit-transform-origin: 50% 0;
    transform-origin: 50% 0;
    -webkit-transform: rotateX(-20deg);
    transform: rotateX(-20deg);
}
@-webkit-keyframes fly {
    0% {
        -webkit-transform: rotateX(-120deg) rotateZ(0deg) rotateX(10deg);
        transform: rotateX(-120deg) rotateZ(0deg) rotateX(10deg);
    }
    100% {
        -webkit-transform: rotateX(-120deg) rotateZ(360deg) rotateX(10deg);
        transform: rotateX(-120deg) rotateZ(360deg) rotateX(10deg);
    }
}
@keyframes fly {
    0% {
        -webkit-transform: rotateX(-120deg) rotateZ(0deg) rotateX(10deg);
        transform: rotateX(-120deg) rotateZ(0deg) rotateX(10deg);
    }
    100% {
        -webkit-transform: rotateX(-120deg) rotateZ(360deg) rotateX(10deg);
        transform: rotateX(-120deg) rotateZ(360deg) rotateX(10deg);
    }
}
@-webkit-keyframes wingLeft {
    0% {
        -webkit-transform: rotateY(-40deg);
        transform: rotateY(-40deg);
    }
    100% {
        -webkit-transform: rotateY(40deg);
        transform: rotateY(40deg);
    }
}
@keyframes wingLeft {
    0% {
        -webkit-transform: rotateY(-40deg);
        transform: rotateY(-40deg);
    }
    100% {
        -webkit-transform: rotateY(40deg);
        transform: rotateY(40deg);
    }
}
@-webkit-keyframes wingRight {
    0% {
        -webkit-transform: rotateY(40deg);
        transform: rotateY(40deg);
    }
    100% {
        -webkit-transform: rotateY(-40deg);
        transform: rotateY(-40deg);
    }
}
@keyframes wingRight {
    0% {
        -webkit-transform: rotateY(40deg);
        transform: rotateY(40deg);
    }
    100% {
        -webkit-transform: rotateY(-40deg);
        transform: rotateY(-40deg);
    }
}
@-webkit-keyframes wind {
    0% {
        -webkit-transform: translateY(-300px);
        transform: translateY(-300px);
    }
    100% {
        -webkit-transform: translateY(200px);
        transform: translateY(200px);
    }
}
@keyframes wind {
    0% {
        -webkit-transform: translateY(-300px);
        transform: translateY(-300px);
    }
    100% {
        -webkit-transform: translateY(200px);
        transform: translateY(200px);
    }
}